That exercise in one’s middle years benefits health in later life is perhaps no surprise given our current understanding of its benefits, but and MRI study has shown to influence the brain’s structure in later years.
Using MRI scans, high levels (150 minutes per week or more) of self-reported moderate-to-high physical activity were associated with reduced risk of lacunar infarct in late life (OR 0.68, 95% CI 0.46-0.99) and more intact white matter integrity.
“Our study suggests that getting at least an hour and 15 minutes of moderate-to-vigorous intensity physical activity a week or more during midlife may be important throughout your lifetime for promoting brain health and preserving the actual structure of your brain,” said Priya Palta, PhD, of Columbia University Irving Medical Center. “In particular, engaging in more than 2 and a half hours of physical activity per week in middle age was associated with fewer signs of brain disease.”
There has been mixed evidence linking physical activity to brain measures or improvements in cognitive function. PhDs Nicole Spartano, of Boston University School of Medicine, and Leonardo Pantoni, MD, of University of Milan, noted in an accompanying editorial that the “most consistent evidence for the protective effect of physical activity against dementia risk has been reported to be leisure time physical activity, and it is unclear whether there is benefit to other types of physical activity that may be less ‘enriching.'”
“It is possible that future work will uncover the requirement that physical activity interventions to reduce dementia risk actually have an enriching element, such as in leisure-time activities, rather than be strictly rote, mechanical movement,” Spartano and Pantoni added.
Recruiting 1 604 individuals with a mean baseline age of 54, the participants had five examinations over 25 years and MRI at a mean age of 72. At baseline (1987-1989) and 25 years later, participants had their moderate-to-vigorous physical activity assessed in a questionnaire.
At midlife, 11% had low levels of moderate-to-high intensity activity (1 to 74 minutes a week), 16% middle levels (75 to 149 minutes a week), and 39% high levels (150 minutes a week or more), with the remainder reporting none.
High moderate-to-vigorous midlife activity was associated with better white matter integrity in late life, compared with no moderate-to-vigorous midlife activity, but there was no association with grey matter volume.
While the risk of lacunar infarcts were lower with more intense midlife activity, risk of cortical infarcts or subcortical microhemorrhage were not. “The associations of greater levels of mid-life physical activity with fewer lacunar (but not cortical) infarcts and greater white matter microstructural integrity suggest cerebrovascular mechanisms are primarily at play,” Palta and colleagues wrote.
When adjusted for vascular risk factors, the association of midlife physical activity to lacunar infarcts was weakened, but the association with white matter microstructure. The editorialists said that it implies that “evidence from this study supports a hypothesis that the mechanisms linking physical activity and the brain are likely multi-dimensional, including mechanisms other than simply improving cerebrovascular health.”
Late-life moderate-to-vigorous physical activity also was associated with most brain measures compared with no moderate-to-vigorous activity, but as this was a prospective study that spanned decades, the “association between midlife physical activity levels and later-life brain imaging features makes a much stronger case for causality than does the same relationship when measured only in late life,” the researchers noted.
The study had several limitations, which included using self-reported data, did not include non leisure-related activity, and participant attrition.
Source: MedPage Today
Journal information: Source Reference: Palta P, et al. A prospective analysis of leisure-time physical activity in midlife and beyond and brain damage on MRI in older adults, Neurology 2020; DOI: 10.1212/WNL.0000000000011375.
